1/* thread_info.h: description 2 * 3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * Derived from include/asm-i386/thread_info.h 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13#ifndef _ASM_THREAD_INFO_H 14#define _ASM_THREAD_INFO_H 15 16#ifdef __KERNEL__ 17 18#ifndef __ASSEMBLY__ 19#include <asm/processor.h> 20#endif 21 22#define THREAD_SIZE 8192 23 24/* 25 * low level task data that entry.S needs immediate access to 26 * - this struct should fit entirely inside of one cache line 27 * - this struct shares the supervisor stack pages 28 * - if the contents of this structure are changed, the assembly constants must also be changed 29 */ 30#ifndef __ASSEMBLY__ 31 32struct thread_info { 33 struct task_struct *task; /* main task structure */ 34 struct exec_domain *exec_domain; /* execution domain */ 35 unsigned long flags; /* low level flags */ 36 unsigned long status; /* thread-synchronous flags */ 37 __u32 cpu; /* current CPU */ 38 int preempt_count; /* 0 => preemptable, <0 => BUG */ 39 40 mm_segment_t addr_limit; /* thread address space: 41 0-0xBFFFFFFF for user-thead 42 0-0xFFFFFFFF for kernel-thread 43 */ 44 struct restart_block restart_block; 45 46 __u8 supervisor_stack[0]; 47}; 48 49#else /* !__ASSEMBLY__ */ 50 51#include <asm/asm-offsets.h> 52 53#endif 54 55#define PREEMPT_ACTIVE 0x10000000 56 57/* 58 * macros/functions for gaining access to the thread information structure 59 * 60 * preempt_count needs to be 1 initially, until the scheduler is functional. 61 */ 62#ifndef __ASSEMBLY__ 63 64#define INIT_THREAD_INFO(tsk) \ 65{ \ 66 .task = &tsk, \ 67 .exec_domain = &default_exec_domain, \ 68 .flags = 0, \ 69 .cpu = 0, \ 70 .preempt_count = 1, \ 71 .addr_limit = KERNEL_DS, \ 72 .restart_block = { \ 73 .fn = do_no_restart_syscall, \ 74 }, \ 75} 76 77#define init_thread_info (init_thread_union.thread_info) 78#define init_stack (init_thread_union.stack) 79 80/* how to get the thread information struct from C */ 81register struct thread_info *__current_thread_info asm("gr15"); 82 83#define current_thread_info() ({ __current_thread_info; }) 84 85/* thread information allocation */ 86#ifdef CONFIG_DEBUG_STACK_USAGE 87#define alloc_thread_info(tsk) \ 88 ({ \ 89 struct thread_info *ret; \ 90 \ 91 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \ 92 if (ret) \ 93 memset(ret, 0, THREAD_SIZE); \ 94 ret; \ 95 }) 96#else 97#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL) 98#endif 99 100#define free_thread_info(info) kfree(info) 101 102#endif /* __ASSEMBLY__ */ 103 104/* 105 * thread information flags 106 * - these are process state flags that various assembly files may need to access 107 * - pending work-to-be-done flags are in LSW 108 * - other flags in MSW 109 */ 110#define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 111#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ 112#define TIF_SIGPENDING 2 /* signal pending */ 113#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 114#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ 115#define TIF_IRET 5 /* return with iret */ 116#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */ 117#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ 118#define TIF_MEMDIE 17 /* OOM killer killed process */ 119#define TIF_FREEZE 18 /* freezing for suspend */ 120 121#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 122#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 123#define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 124#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 125#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 126#define _TIF_IRET (1 << TIF_IRET) 127#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) 128#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) 129#define _TIF_FREEZE (1 << TIF_FREEZE) 130 131#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */ 132#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */ 133 134/* 135 * Thread-synchronous status. 136 * 137 * This is different from the flags in that nobody else 138 * ever touches our thread-synchronous status, so we don't 139 * have to worry about atomic accesses. 140 */ 141#define TS_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */ 142 143#endif /* __KERNEL__ */ 144 145#endif /* _ASM_THREAD_INFO_H */ 146